Flotation of gold minerals

Gold deposits can be divided into two major categories: sand gold and vein gold. Sand gold is weathered from endogenous deposits. There are 20 kinds of gold-bearing minerals, mainly natural gold (alloying elements gold, silver, copper and the like), gold silver, tellurium, gold and the like. Associated elements according to their type, arsenic gold ore, gold sulfide ores, gold and copper, gold antimony, gold, uranium, gold and so on Ore.
The size of gold inlays varies from 2 mm to 1 mm, and can be less than 1 to 5 pum. Because gold has a high density of 15.3 to 18.3 g/cm, coarse particles can be treated by various re-selection (including soil washing) + amalgamation , and small exposed particles can be leached with cyanide or thiourea. Medium-sized (0.001 to 0.070 mm) monomer gold or gold embedded in various metal sulfides is treated by flotation. The floatability of gold is related to the size, shape and surface state of its particle size. Coarse grain gold easily falls off the surface of the foam. The flaky gold is relatively easy to float, and the round granulated gold is more difficult to float. Buoyant pure gold surface, the surface is iron oxide or other hydrophilic contaminated gold floatability difference. Silver-containing gold particles are more buoyant than pure gold particles. Some natural gold floats very well and floats automatically on the surface of the water. Generally, the flotation of gold does not require an activator, but the addition of sodium carbonate can precipitate certain metal ions and maintain the pH at 8-9, which is beneficial to the flotation of natural gold. Copper sulphate can increase the flotation rate of gold, but it is more harmful.
Natural gold inhibitors are 0H- (pH greater than 11), Ca2+, CN-, Na2S, sodium sulfite, sodium silicate, tannin, heavy metal ions. The best flotation of natural gold is also E +10 ~ +50mV (Pt electrode to calomel electrode). When pyrite contains gold, the pH can be reduced to 4.
The collectors of flotation gold mainly include xanthate, black medicine, Z-200, thiol benzothiazole, thiourea, carbamate and the like. In recent years, China has used Y89, Jinlingling and other flotation of natural gold and gold-containing copper sulfide and other multi-metallic minerals, the effect is remarkable. In Russia, it is recommended to use a combination of TAA (thioacyl anilide) R-404 and butyl potassium xanthate (BKK), and to obtain the best combination of TAA and BKK in multiple combinations.